Detailed explanation of the working principle of high frequency inverter

High-frequency inverter electrical appliances are a kind of switching equipment used in the industrial field. What is the working principle of high-frequency inverters? This equipment is controlled by program logic. High frequency inverter can be used in the telecommunications industry and is a switching device in computer rooms. This kind of power supply can be used in the solar energy industry and power generation industry. It is a switching power supply device that uses data line output and is very safe. This article mainly introduces the working principle of high-frequency inverter and the difference between high-frequency inverter and low-frequency inverter. Follow the editor to learn more.

A high-frequency inverter is a DC to AC transformer. It is actually a voltage inversion process with a converter. The working principle of the high-frequency inverter is that the converter converts the AC voltage of the power grid into a stable 12V DC output, while the inverter converts the 12V DC voltage output by the Adapter into high-frequency, high-voltage AC power; both parts are equally The widely used pulse width modulation (PWM) technology is adopted. Its core part is a PWM integrated controller, the Adapter uses UC3842, and the inverter uses TL5001 chip. The operating voltage range of TL5001 is 3.6~40V. It is equipped with an error amplifier, a regulator, an oscillator, a PWM generator with dead zone control, a low-voltage protection circuit and a short-circuit protection circuit.

1. Input connection part: The input part has 3 signals, 12V DC input VIN, working enable voltage ENB and Panel current control signal DIM. VIN is provided by the Adapter, and the ENB voltage is provided by the MCU on the motherboard. Its value is 0 or 3V. When ENB=0, the inverter does not work, and when ENB=3V, the inverter is in normal working condition and the DIM voltage is Provided by the mainboard, its variation range is between 0~5V. Different DIM values are fed back to the feedback terminal of the PWM controller. The current provided by the inverter to the load will also be different. The smaller the DIM value, the smaller the current output by the inverter. The bigger.

2. Voltage starting circuit: When ENB is at a high level, it outputs high voltage to light up the Panel's backlight tube.
3. PWM controller: It has the following functions: internal reference voltage, error amplifier, oscillator and PWM, overvoltage protection, undervoltage protection, short circuit protection, and output transistor.

4. DC conversion: A voltage conversion circuit is composed of a MOS switching tube and an energy storage inductor. The input pulse is amplified by a push-pull amplifier and drives the MOS tube to perform switching actions, so that the DC voltage charges and discharges the inductor, so that the other end of the inductor can Get AC voltage.

5. LC oscillation and output circuit: ensure the 1600V voltage required to start the lamp, and reduce the voltage to 800V after the lamp is started.

6. Output voltage feedback: When the load is working, the sampling voltage is fed back to stabilize the inverter voltage output.

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